4BT Cummins conversion

[Todom711]

Hello everyone,

I have a 92 FJ80 getting built for a trail buggy. I was looking at dropping a 4BT cummins in place of the 3FE. The questions i have is it worth it? Also what is cost and time frame usually for this kind of conversion and is this the best way to go? Nothing against the 3FE but its kind of a turd.

 

[maxamillion2345]

No offense dude and I do hope you find the answers you're looking for but as a guy whose done a 6bt swap and seen this thread a million times, if you have to ask...

I'll say this though. Worth it. Not cheap. Gonna take a while. Lots and lots of info on here.

 

[Todom711]

none taken. Again im new I dont know what the best way to go about this. Just curious and testing the waters. If you have done a 6BT swap was it worth it? How much did you have in it?

 

[maxamillion2345]

If this isnt a fun project or you don't have a lot of money to pay someone else to do this professionally... then itd be difficult to say its worth it. For me, sure I love it. However, its a bottomless money pit and a neverending project in some form or another. I think most here who have done a cummins swap would agree.

Id start reading every cummins swap thread. Pay attention to the jonesys one, fxxx that guy, and then on to duiser and now whatever the hell they are that Dustin does his kit. Be wary of the issues that come along with Dustin, nice kit, poor service.

4bts are a weird engine as theres so many variations so I'd shoot for a p pumped one personally.

Lots of threads with multiple ways to do this swap.

 

[Todom711]

i gotcha sounds like i opened pandoras box lol. Would there be a gas engine conversion thats easier? Like the 4.7?

 

[Warpigg]

I know nothing of the 4bt swaps in these but was told that the Isuzu diesel 4 cyl found in the npr's are more road friendly then the Cummins units. Like a more usable rpm range and such. The engine code is similar to the 4bt. I think they can be had for cheaper then the Cummins one since people see that Cummins name tags and think they have a jewel. At least that's how it is here in vermont

 

[Todom711]

What’s the average cost you see of swapping them over?

 

[JaketheSSnake]

Honestly if it's just a trail buggy, you should look at re-gearing it and or running a doubler. If you really need more power it's hard to beat an LS swap. Cheaper and easier than a diesel

 

[inkpot]

If you want a hardcore trail buggy it may be cheaper to just build one from scratch from a better platform. If you want something a little less dedicated, then 5.29 gears on the axles and crawler gears in the transfer case may be all you need.

 

[DIESELJEEP]

IMHO a 4bt should only be considered when space is a concern.Since that's not the case in an 80,go with a 6bt(12v cummins).The power and torque of these engines is what you want.In my case it was very much worth the swap.My cruiser is a pleasure to drive now compared to when it was a gasser.Cost depends if you do it or pay for it to be done,so that varies widely ($6000-$25,000).Took around 80 hours to complete the swap myself.

 

[Todom711]

i bet it was. The 6BT would be sick in that ride. From what i saw it looked like it was more effort to convert than the 4BT but again im going off speculation i really have no idea.

 

[cjmoon]

i bet it was. The 6BT would be sick in that ride. From what i saw it looked like it was more effort to convert than the 4BT but again im going off speculation i really have no idea.

you have way more room to work with on the 6bt just not in front. changing fuel filter or lift pump on my 4bt is a bitch, changing the starter or pulling power steering pump takes a lot of time removing things like the lift pump might be needed. cussing cut up hands and what not, but you just reach in on the 6bt. the driver side gets tight with injection pump steering and brakes.the length help spread all those things out. on the passenger side the turbo is further forward and there for not up against the fire wall. i made a custom manifold and have a tight radius down pipe to get he turbo forwards a few more inches .

price i did it on the cheap 7-8k after rebuild and aftermarket used trans controller with 100's of hours tweeking making things better over the years i'm 100's of hours including mods after the fact to improve or repair

 

[BILT4ME]

Check out this guy's thread.
4bt cummins 96 FZJ

 

[Mr Cimarron]

I don't think a 6bt would be a good fit for a trail buggy. Too heavy. Both 4bt and 6bt would be pretty loud in a buggy as well since you won't have a cab to hide in.

 

[Technician1985]

The gas engine is free and should have enough power with lower gearing right?